/* =================================
   NordVPN 网站统一样式表 - 终极修复版
   符合中文阅读习惯，LTR布局
   ================================= */

/* =================================
   变量定义
   ================================= */
:root {
  --primary-color: #003366;
  --secondary-color: #0056b3;
  --accent-color: #ffc107;
  --dark-color: #343a40;
  --light-color: #f8f9fa;
  --text-color: #333;
  --card-color: #fff;
  --border-color: #e7e7e7;
  --success-color: #28a745;
  --border-radius: 8px;
  --box-shadow: 0 4px 8px rgba(0,0,0,0.08);
  --box-shadow-hover: 0 8px 16px rgba(0,0,0,0.12);
  --transition: all 0.3s ease;
}

/* =================================
   全站通用样式（符合中文阅读习惯，LTR）
   ================================= */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', 'Heiti SC', system-ui, -apple-system, Arial, sans-serif;
  background-color: var(--light-color);
  color: var(--text-color);
  line-height: 1.75;
  text-align: left; /* 中文常用从左至右排版 */
}

.container {
  max-width: 1200px;
  margin: auto;
  padding: 20px;
}

/* =================================
   头部导航 - 修复移动端菜单
   ================================= */
header {
  background: var(--card-color);
  padding: 15px 0;
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.nav-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: relative;
}

.logo {
  font-size: 1.8em;
  font-weight: bold;
  color: var(--primary-color);
  text-decoration: none;
  z-index: 1001;
}

.nav-menu {
  display: flex;
  gap: 30px;
  align-items: center;
}

.nav-menu a {
  color: var(--primary-color);
  text-decoration: none;
  padding: 10px 15px;
  font-weight: 600;
  transition: var(--transition);
  border-radius: 4px;
}

.nav-menu a:hover,
.nav-menu a:focus {
  color: var(--secondary-color);
  background-color: rgba(0, 86, 179, 0.05);
}

.btn-cta {
  background-color: var(--accent-color);
  color: var(--text-color);
  padding: 12px 25px;
  text-decoration: none;
  border-radius: var(--border-radius);
  font-weight: bold;
  transition: var(--transition);
  white-space: nowrap;
  display: inline-block;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.btn-cta:hover,
.btn-cta:focus {
  background-color: #e0a800;
  box-shadow: 0 4px 10px rgba(0,0,0,0.15);
  transform: translateY(-2px);
}

/* 桌面端CTA按钮 */
.desktop-only {
  display: block;
}

/* =================================
   移动端汉堡菜单 - 修复点击问题
   ================================= */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 21px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1001;
  position: relative;
}

.menu-toggle span {
  display: block;
  height: 3px;
  width: 100%;
  background-color: var(--primary-color);
  border-radius: 3px;
  transition: var(--transition);
  transform-origin: center;
}

.menu-toggle.active span:nth-child(1) {
  transform: translateY(9px) rotate(45deg);
}

.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
  transform: translateY(-9px) rotate(-45deg);
}

/* =================================
   菜单遮罩层
   ================================= */
.menu-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  z-index: 999;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
  pointer-events: none;
}

.menu-overlay.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* =================================
   页脚
   ================================= */
footer {
  background: var(--dark-color);
  color: #fff;
  text-align: center;
  padding: 20px 0;
  margin-top: 40px;
}

/* =================================
   通用内容区块
   ================================= */
.page-header {
  background: var(--primary-color);
  color: #fff;
  padding: 40px 20px;
  text-align: center;
}

.page-header h1 {
  font-size: 2.5em;
  margin: 0;
}

.content-section {
  background: var(--card-color);
  padding: 40px;
  margin: 30px auto;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  max-width: 900px;
}

.content-section h2 {
  color: var(--secondary-color);
  margin-top: 0;
  border-bottom: 2px solid var(--accent-color);
  padding-bottom: 10px;
}

.center-btn {
  text-align: center;
  margin-top: 40px;
}

/* =================================
   首页样式
   ================================= */
.hero {
  background: var(--primary-color);
  color: #fff;
  padding: 60px 20px;
  text-align: center;
}

.hero h1 {
  font-size: 2.6em;
  margin: 0 0 16px 0;
}

.hero p {
  font-size: 1.1em;
  margin: 0 0 28px 0;
  opacity: 0.9;
}

.section {
  padding: 50px 0;
}

.section h2 {
  text-align: center;
  margin-bottom: 40px;
  font-size: 2.1em;
  color: var(--primary-color);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 30px;
}

.card {
  background: var(--card-color);
  padding: 28px;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: var(--box-shadow-hover);
}

.card h3 {
  color: var(--secondary-color);
  border-bottom: 2px solid var(--accent-color);
  padding-bottom: 10px;
  margin-top: 0;
}

/* 列表与对勾符号（适配 LTR） */
.card ul,
.features-list,
.pricing-features ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

.card ul li,
.features-list li,
.pricing-features li {
  padding-left: 28px;
  position: relative;
  margin-bottom: 10px;
}

.card ul li::before,
.features-list li::before,
.pricing-features li::before {
  content: '✓';
  color: var(--success-color);
  position: absolute;
  left: 0;
  font-weight: bold;
  line-height: 1;
}

.faq-item {
  margin-bottom: 20px;
  background: var(--card-color);
  padding: 20px;
  border-radius: 6px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  transition: var(--transition);
}

.faq-item:hover {
  box-shadow: 0 4px 8px rgba(0,0,0,0.08);
}

.faq-item h4 {
  margin: 0 0 10px 0;
  color: var(--secondary-color);
  font-size: 1.1em;
}

.banners {
  display: flex;
  justify-content: space-around;
  flex-wrap: wrap;
  gap: 20px;
  margin-top: 40px;
}

.banner {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  border-radius: var(--border-radius);
  padding: 30px;
  color: white;
  text-align: center;
  flex: 1;
  min-width: 280px;
  box-shadow: var(--box-shadow);
}

.banner h3 {
  font-size: 1.5rem;
  margin-bottom: 10px;
}

/* =================================
   功能特色页面样式
   ================================= */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.feature-card {
  background: var(--card-color);
  padding: 30px;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  border-left: 4px solid var(--accent-color);
}

.feature-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--box-shadow-hover);
}

.feature-card h3 {
  color: var(--secondary-color);
  margin-top: 0;
  display: flex;
  align-items: center;
}

.feature-icon {
  font-size: 1.8em;
  margin-right: 12px;
}

.feature-card p {
  margin-bottom: 20px;
}

.feature-banner {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  border-radius: var(--border-radius);
  padding: 40px;
  color: white;
  text-align: center;
  margin: 40px 0;
  box-shadow: var(--box-shadow);
}

.feature-banner h2 {
  margin-top: 0;
  color: #fff;
  border-bottom: none;
}

.feature-banner .btn-cta {
  background-color: var(--accent-color);
  color: var(--text-color);
  margin-top: 20px;
}

/* =================================
   使用指南页面样式
   ================================= */
.tutorial-section {
  margin-bottom: 50px;
}

.tutorial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 30px;
}

.platform-card {
  background: var(--card-color);
  padding: 25px;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  border-top: 4px solid var(--accent-color);
  text-align: center;
}

.platform-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--box-shadow-hover);
}

.platform-icon {
  font-size: 3em;
  margin-bottom: 15px;
  display: block;
}

.platform-card h3 {
  color: var(--secondary-color);
  margin-top: 0;
}

.platform-card .btn-cta {
  display: inline-block;
  margin-top: 15px;
  padding: 8px 16px;
  font-size: 0.9em;
}

.step-by-step {
  margin-top: 40px;
}

.step {
  display: flex;
  margin-bottom: 40px;
  align-items: flex-start;
}

.step-number {
  background-color: var(--primary-color);
  color: white;
  border-radius: 50%;
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: bold;
  font-size: 1.2em;
  margin-right: 20px;
  flex-shrink: 0;
}

.step-content {
  flex: 1;
}

.step-content h3 {
  color: var(--secondary-color);
  margin-top: 0;
}

.step-image {
  background-color: #e9ecef;
  border-radius: var(--border-radius);
  height: 200px;
  margin: 15px 0;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #6c757d;
  font-style: italic;
}

.tip-box {
  background-color: #e7f3ff;
  border-left: 4px solid var(--secondary-color);
  padding: 15px 20px;
  margin: 20px 0;
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.tip-box strong {
  color: var(--secondary-color);
}

.troubleshooting-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin-top: 30px;
}

.troubleshooting-item {
  background: var(--card-color);
  padding: 20px;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  border-left: 4px solid var(--success-color);
  transition: var(--transition);
}

.troubleshooting-item:hover {
  box-shadow: 0 4px 8px rgba(0,0,0,0.08);
}

.troubleshooting-item h4 {
  color: var(--secondary-color);
  margin-top: 0;
}

/* =================================
   套餐价格页面样式
   ================================= */
.pricing-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.pricing-card {
  background: var(--card-color);
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  overflow: hidden;
  transition: var(--transition);
  position: relative;
}

.pricing-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--box-shadow-hover);
}

.pricing-card.popular {
  border: 2px solid var(--accent-color);
  transform: scale(1.05);
}

.pricing-card.popular:hover {
  transform: scale(1.05) translateY(-5px);
}

.popular-badge {
  background: var(--accent-color);
  color: var(--text-color);
  text-align: center;
  padding: 8px;
  font-weight: bold;
  font-size: 0.9em;
}

.pricing-header {
  background: var(--primary-color);
  color: white;
  padding: 25px 20px;
  text-align: center;
}

.pricing-header h3 {
  margin: 0;
  font-size: 1.5em;
}

.pricing-price {
  margin: 15px 0 0;
  font-size: 2.5em;
  font-weight: bold;
}

.pricing-period {
  font-size: 0.9em;
  opacity: 0.8;
  margin-top: 5px;
}

.pricing-savings {
  background: #e7f3ff;
  color: var(--secondary-color);
  padding: 8px;
  text-align: center;
  font-weight: bold;
  font-size: 0.9em;
}

.pricing-features {
  padding: 25px 20px;
}

.pricing-footer {
  padding: 0 20px 25px;
  text-align: center;
}

.pricing-footer .btn-cta {
  width: 100%;
  box-sizing: border-box;
  text-align: center;
}

.features-comparison {
  margin-top: 50px;
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 20px;
}

.comparison-table th,
.comparison-table td {
  padding: 15px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
  background-color: var(--light-color);
  color: var(--primary-color);
  font-weight: 600;
}

.comparison-table tr:last-child td {
  border-bottom: none;
}

.feature-check {
  color: var(--success-color);
  font-weight: bold;
}

.feature-missing {
  color: #6c757d;
}

.payment-methods {
  display: flex;
  flex-wrap: wrap;
  gap: 15px;
  margin-top: 20px;
  justify-content: center;
}

.payment-method {
  background: var(--light-color);
  padding: 10px 15px;
  border-radius: 6px;
  font-size: 0.9em;
}

.guarantee-banner {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  border-radius: var(--border-radius);
  padding: 40px;
  color: white;
  text-align: center;
  margin: 40px 0;
  box-shadow: var(--box-shadow);
}

.guarantee-banner h2 {
  margin-top: 0;
  color: #fff;
  border-bottom: none;
}

.guarantee-banner .btn-cta {
  background-color: var(--accent-color);
  color: var(--text-color);
  margin-top: 20px;
}

/* =================================
   技术支持页面样式
   ================================= */
.support-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.support-card {
  background: var(--card-color);
  padding: 30px;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  text-align: center;
  border-top: 4px solid var(--accent-color);
}

.support-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--box-shadow-hover);
}

.support-icon {
  font-size: 3em;
  margin-bottom: 15px;
  display: block;
}

.support-card h3 {
  color: var(--secondary-color);
  margin-top: 0;
}

.support-card .btn-cta {
  display: inline-block;
  margin-top: 15px;
  padding: 10px 20px;
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
  margin-top: 30px;
}

.contact-card {
  text-align: center;
  padding: 25px;
  border: 1px solid #eee;
  border-radius: var(--border-radius);
  transition: var(--transition);
}

.contact-card:hover {
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

.contact-card h3 {
  color: var(--secondary-color);
  margin-top: 0;
}

.contact-card p a {
  color: #007bff;
  text-decoration: none;
  font-weight: 600;
}

.contact-card p a:hover,
.contact-card p a:focus {
  text-decoration: underline;
}

.icon {
  font-size: 2.5em;
  color: var(--primary-color);
  margin-bottom: 15px;
}

.faq-categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin-top: 30px;
}

.faq-category {
  background: var(--card-color);
  padding: 20px;
  border-radius: var(--border-radius);
  box-shadow: 0 2px 4px rgba(0,0,0,0.05);
  transition: var(--transition);
}

.faq-category:hover {
  box-shadow: 0 4px 8px rgba(0,0,0,0.08);
}

.faq-category h3 {
  color: var(--secondary-color);
  margin-top: 0;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 10px;
}

.faq-category ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

.faq-category li {
  margin-bottom: 10px;
}

.faq-category li a {
  color: var(--text-color);
  text-decoration: none;
  transition: var(--transition);
}

.faq-category li a:hover {
  color: var(--secondary-color);
}

.status-banner {
  background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
  border-radius: var(--border-radius);
  padding: 25px;
  color: white;
  text-align: center;
  margin: 40px 0;
  box-shadow: var(--box-shadow);
}

.status-banner h2 {
  margin-top: 0;
  color: #fff;
  border-bottom: none;
}

.status-indicator {
  display: inline-block;
  background: var(--success-color);
  color: white;
  padding: 5px 15px;
  border-radius: 20px;
  font-weight: bold;
  margin-bottom: 15px;
}

/* =================================
   响应式设计（移动端优化）- 修复菜单点击问题
   ================================= */
@media (max-width: 768px) {
  .nav-bar {
    flex-wrap: wrap;
  }
  
  .menu-toggle {
    display: flex;
  }
  
  .nav-menu {
    position: fixed;
    top: 0;
    right: -100%;
    width: 80%;
    max-width: 300px;
    height: 100vh;
    background: var(--card-color);
    flex-direction: column;
    justify-content: flex-start;
    align-items: flex-start;
    gap: 0;
    padding: 80px 20px 20px;
    transition: right 0.3s ease;
    box-shadow: -5px 0 15px rgba(0,0,0,0.1);
    overflow-y: auto;
    z-index: 1000;
  }
  
  .nav-menu.active {
    right: 0;
  }
  
  .nav-menu a {
    width: 100%;
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
    font-size: 1.1em;
    display: block;
    pointer-events: auto;
  }
  
  .nav-menu a:last-child {
    border-bottom: none;
  }
  
  .nav-menu .btn-cta {
    margin-top: 20px;
    width: 100%;
    text-align: center;
    pointer-events: auto;
  }
  
  .desktop-only {
    display: none;
  }
  
  .hero h1 {
    font-size: 2em;
  }
  
  .page-header h1 {
    font-size: 2em;
  }
  
  body {
    text-align: left;
  }
  
  .banners {
    flex-direction: column;
  }
  
  .pricing-grid,
  .support-options,
  .contact-grid,
  .faq-categories,
  .troubleshooting-grid {
    grid-template-columns: 1fr;
  }
  
  .pricing-card.popular {
    transform: none;
  }
  
  .pricing-card.popular:hover {
    transform: translateY(-5px);
  }
  
  .step {
    flex-direction: column;
  }
  
  .step-number {
    margin-right: 0;
    margin-bottom: 15px;
  }
  
  .comparison-table {
    font-size: 0.9em;
  }
  
  .comparison-table th,
  .comparison-table td {
    padding: 10px 5px;
  }
  
  /* 防止滚动当菜单打开时 */
  body.menu-open {
    overflow: hidden;
  }
  
  /* 菜单背景遮罩 */
  .menu-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
    pointer-events: none;
  }
  
  .menu-overlay.active {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
  }
}

/* 小屏幕设备优化 */
@media (max-width: 480px) {
  .container {
    padding: 10px;
  }
  
  .content-section {
    padding: 20px;
  }
  
  .hero {
    padding: 40px 20px;
  }
  
  .section {
    padding: 30px 0;
  }
  
  .grid,
  .feature-grid,
  .tutorial-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .card,
  .feature-card,
  .platform-card {
    padding: 20px;
  }
  
  .nav-menu {
    width: 85%;
  }
}